[Changes in noradrenaline-induced vasoconstriction through ouabain blockade of the transmembranal electrolyte distribution].

In continuation of their studies concerning changes in the reactivity of vascular segments under isolated perfusion in vivo with simultaneous experimental disturbance of transmembranous distribution of electrolytes, the authors investigated in ten rabbits the effect of noradrenaline in the ear with isolated circulation. After perfusion of an ouabain solution (total concentration: 0.4 X 10(-5) M), in dependence on the duration of the effect of glycoside the vasoconstrictor response to 0.1 and 0.5 micrograms noradrenaline was significantly strengthened, up to 40% of the initial value. After washing-out of the vascular segment under isolated perfusion with Krebs-Henseleit solution, and ensuing restoration of normal cation relationships, the vascular reactivity returned to its initial level. Potential analogous mechanisms of the etiology and pathogenesis of essential hypertension are discussed.